Bacterial key species candidates for biomonitoring peatland burnt in the Giam Siak Kecil-Bukit Batu biosphere reserve, Riau

Abstract

Peatland fires affect the diversity of bacteria, particularly key species bacteria (BKS). BKS has an important role in the structure of ecological community as key taxa to forming the composition and function. This study determined unique BKS candidates of the secondary forest which may not be found in burned areas. These candidates were detected in silico from the 16S rRNA gene sequence. The 16S rRNA gene sequence was determined by next-generation sequencing (NGS) method from peat soil DNA sampled from secondary forest and burned areas in the Giam Siak Kecil Biosphere Reserve, Bukit Batu (GSK-BB). BKS candidates were selected from a phylogenetic tree constructed by using MEGA version 6.06. Selected BKS was in the same cluster as secondary forest and were re-selected using BLASTn: AlignTwo or More Sequence analysis to ensure the uniqueness of the sequences. Based on the selected candidates, specific primers were designed to amplify the 16S rRNA BKS gene. Sensitivity was tested in silico using FastPCR application to ensure that candidates were only in secondary forest. There were 19 BKS candidates found in the secondary forest and not in burnt land (BKS_SFB) that were classified into three groups. Based on the in silico PCR amplification of the 16S rRNA gene using the designed primer, we obtained two high specificity BKS candidates, i.e. BKS SFB2 (455 bp) and BKS SFB3 (473 bp). The two candidates are potential as DNA barcodes for peatland quality monitoring after burning.